1. Field of the Invention
This invention relates to the treating of optical fibers in general, and more particularly to an apparatus for treating optical fibers by spark erosion.
2. The Prior Art
Optical fibers (sometimes referred-to as "fiber optics") are by now well established in a variety of applications. For example, in automobiles they are used to monitor the condition of certain lights (e.g. tail lights) to aprise the operator that the lights are functioning. Other applications have been developed for the home (mostly decorative), for the military and for industry. The widest use of optical fibers is found in industry where they are employed as wave guides to transmit signals, pictures and the like. It will be recalled that the principle of operation of optical fibers is that these fibers, which are usually of glass, are provided with an external reflective coating and then when light is applied to one end face of the fiber it is transmitted to the other end face of the fiber by a process of total reflection.
It is extremely important that the end face of each optical fiber be as smooth as possible and be located as closely as possible in a plane extending normal to the elongation of the fiber so that, if the end faces of two fibers are connected, or where the fibers are connected to the optical sender or receiver, minimum light losses will occur. This problem has been realized and attempts have been made to meet these requirements, namely to make the end faces of the fibers planar and located in a plane extending normal to the elongation of the fibers. One approach was described by Gloge, Smith, Bisbee and Chinnock in "Optical Fiber End Preparation for Low-loss Splices", Bell Systems Technology Journal, 1973, 52, pp. 1579-1588 and also by Murata, Inao, Matsuda and Takahashi in "Splicing of Optical Fiber Cable on Site", IEE Conference publication 1975, No. 132, pp. 93-95. Both sets of authors suggest to bend the fibers over a cylindrical tool having a certain radius of curvature and to slightly score the surface of the fiber with a diamond to cause a break in the fiber due to the stresses which were established in it by bending it over the cylindrical tool. This proposal works very well but is relatively complicated and difficult to carry out so that it is not well suited for commercial applications where it must be possible to employ a process that is simple and therefore inexpensive and which can be carried out by semi-skilled or even unskilled personnel.
Another proposal was made by Caspers and Neumann and described under the title "Optical-Fiber End Preparation by Spark Erosion" in Electronics Letters, Aug. 19, 1976, volume 12, No. 17. According to this proposal the fiber surface is subjected to spark erosion and thereafter the fiber is broken by hand, the break taking place at the point eroded by the sparks and end faces being produced at the break which are smooth and located in a plane normal to the elongation of the fiber. However, no commercially suitable apparatus has heretofore been proposed for carrying this latter proposal into effect.